Automatic back gauge spacer for paper cutters



Jan. 28, 1958 Ac3. THUMIM :TAL

AUTOMATIC BACK GAUGE SPACER FOR PAPER CUTTERS Filed March 14, 1956 5sheet-sneet 1 Jan. 28, 1958' c. THUMIM l-A1. 2,821,252

AUTOMATIC BACK GAUGE SPACER FOR PAPER CUTTERS Filed March 14, 195e 5sheets-sheet 2 m. 28, i958 K c. THUMIM ETAL K AUTOMATIC BACK GAUGESPACER FOR PAPER CUTTERS Filed March 1.4,A 195e 5 Sheets-Sheet 3 24,14 ff Z 6 Arran/M Jan. 28, 1958 c.THUM1M ErAL 2,821,252

AUTOMATIC BACK GAUGE SPACER FOR PAPER cUTTERs Filed March 14, 195e. 5sheets-sheet 4 Jam.. 28, 1958 f c. 'nuumnvA ETRAL 2821, 252

AUTOMATIC BACK GAUGE SPACER FOR PAPER cuT'rERs Filed March 14, 195e 5sheets-sheet 5 United States Patent lice AUTOMATIC BACK GAUGE SPACERFOR' PAPER CUTTERS Carl Thumim, Westbury, N. Y., and Nicholas Herman,Harrington Park, N.J;, assgnors to E; P. Lawson Co., Inc., NewYork, N;Y., corporation of New York Application March 14, 1956, serial No.571,518

12 claims. (c1. 164-59) The present invention relates to improvementsjinautomatic spacing mechanism, specifically in providing fullyelectrically controlled operation of the back gauge of paper cuttingmachines.

The present invention relates to improvements upon paper cuttingmachines as shown anddescrlibed in Patent No. 2,628,680, issued'February 17, 1953, and applications Serial No. 200,013, led December 9,1950, now Patent No. 2,737,158, and`Seria1 No; 391,217, tiled November10, 1953, now abandoned, all assigned to the same assignee as thepresent invention.

In the operation of guillotine type paper cutters, a pile of paper isplaced on the work table beneath the cutting knife. The back gaugeprovided on the work table is adjusted so that the portion of the' pilewhich it is desired to cut off extends forward ofthe cutting knife edge.Thus, when the reciprocable knife'blade is brought down, it will cut onan exactly dimensioned section of the pile.

In operating paper cutters of this type, it frequently becomes necessaryto adjust the position of the back gauge many times for the differentlcuts which are to be made, such as on a printed pile ofV sheets. Even ifa plurality of regular cuts" are to be made from a single pile, the backgauge must be' moved up`e'ach` time to ensure'that thel forward edge ofthe' pile is perfectly squared so that the exactr desired cut mayb'emade.

In the aforesaid pending application, a controlsystem is shown wherebythe' back gaugeis automatically motivated by' spacing mechanism actuatedthrough photoelectric cells in accordance withpredetermined set-ups. Theoperator preset'sstops' along a program member, all related to themovements of therback gauge. The stop set-up is at the operating frontof the cutting machine, as shown and described in the referredV to'applications, and is directly related to the desired cutting strokes tobe performed onv the sheets forming'the pile of work in theV papercutter. Should trim-outs'be required between closely spaced imprints,such as of labels, the' system isadapted to readily perform suchtrim-out cuts as well. The electrical system comprises a singleV lampwhich' flashes whenever the control causes the back gauge to be stoppedso the cutter may be'motivated, as will be described. The lamp indicatesto the operator that the pile is in a desired positionV for cutting` sothat he may activate the reciprocating knife whichco-jointly operatesVwith a clamp, in a mannerfamiliar t'o'those skilled'in the art.

By the 'use of the invention system, the operator need do nothing morethan place theinitial pile of papers on the machine against the back`gauge and arrange a program of cutting with-the stop units. TheVoperator'then actuates the cutter blade each time a signal lamp flashes.The program of stop units controls the spacin'gmech anism so that theback gauge driving mechanism automatically moves the back gauge thenecessary distance after each cut and before the' next cut is started.The

2,821,252 Patented Jan. 28, A1958 2 stopV and trim-out programnriits areused' in conj'iinctin with a carriage containing the photoelectric cellsthat moves' transversely across the front of ,theciltting'nachine insynchronism with the movement of the back gauge.

When the operation of the lbach gauge is initiated, a light beam passesin thev space between stop and impinges' upon the exposed photo-cells;operation takes place at full speed, driving"` theV back gauge: forwardat its rapid speed. At the same time, the carriage" is synchronouslydriven transversely" from right tou eff, through cable attachments tothe back gauge.'v When light toY a photo-cell is first interrupted b'ythe right-,hand edge'A of a stop unit, circuits are operatedthatdirecftly reduce the forward speed ofthe back gauge (and the: car'-ria'ge) toits slow speed of'movement'forward.` L With the carriage nowat 4the slow speed; wheii the lightl beam is` interrupted by the pui ofthe stop nnitLmthe back gaugeand'the carriage are directly haltedintheir movement. Thus, a heavy pile of paperl may be' brought up rapidlyby the back gauge to near the point wherefit is to' be stopped'.Thereafter, it is slowed down; and then finally brought to a stop. Suchslow-down interval prevents a sudden stop of thel heavy back gauge andavoids causing' theY heavy paper pile to cross beyond@ predeterminedposition'. The nal speed of gauge' ma'y be' as little as' 1%y of the-Vfast forward lspeed at which the paper pile is brought up close tothestopl ping point. Preferably, the reinitiation of the back'gaug'ecycle of operation to the next cutting position is` arranged so' thatthe lifting of the knifev and clampl clearl of the paperpile towardstheir nesting position1 resetstlie coni trol apparatus throughv aswitch; A" bylpas'sl switchTv is also 'provided' so that the automaticback gauge cyc'l'may be reset manually whenever desired.

The control elements are' so arranged that-anrst'change; in the lightbeam' conditions on the photorcells due t'o the`right-hand'opaque edgeof a-stop unit'c's'iu'se'stheback` gauge to be slowed down, andasecondrv change' inthe light condition, due to the arrangement' ofthe's't'opui't after initiationr'of the slow' operation will causejtlie'b'acliJ gaugev to be directly stopped. That is',l thedarke'ningof aiii-st photo-sensitive element' causes' a slow down, and the darkening'of afsecond'photo-sensitive elementscas the control means to stopthe'ba'ck gauge. Y

Whenthecutting machine is usedtocut labels'for other material printedupon the sheets of the pileof paper', the back gauge' is requiredtonrove forward inchtorfm between each cutting operation.V I However, onprinted sheets where many rows of labels o'r'the like appear, there' isalso found a small strip such as between-H6 to'v 3X1 that' remainsunprinted. Such' unprin'ted; areas* are` due to the plate hooks whichare located between' adjacent printing plates for clamping these plates'to'the' printing cylinder, as is known in the art. Hence, after'the;l'a'cltv4 gauge' has been'rno'ved forward several cycles" of'` fastAto slow speed to stop'for cutting a` series' ofv printedflabel rows, itbecomes necessary that the back gauge be'nioved forward by onlyafractionof an inch to' permit the cutL ting or trim out of the smallunprinted'strips: Ins'uchy case, after a' main cut, the back' gaugestarts to move forward at its slow speed and then toa stopfor'v thenearby trim out cut. For the purpose of trimmingv outV the narrowunprinted strips o f paper, a separate stop unitY stopped position onlyat a slow speed, travelsfa'fr',a'ctitin'al4 part of an inchprogrammedfor it and thenfcomesfto a stop vfor the cutting out ortrimming out of the; unprinted" Strip Assuming that a trim out stop unitis adjacent a regulai stop unit, a slit of only the required fractionalinch will exist between the lower parts of the two stop units throughwhich the light beam can pass. If the green signal light has flashed,indicating that an accurate stop has been made, the operator can thenstart the cutting blade operation. The knife blade on its return upwardmovement operates the recycling switch, initiating thereupon the slowspeed of the back gauge, since the light beam is blocked after passingthe narrow slit for the first cut. The back gauge continues to advanceat the slow lspeed until the control light beam in the carriage reachesthe trim out unit. At this point, the light beam is interrupted to causethe electrically controlled driving mechanism of the invention to bringthe back gauge to a stop. The green signal light indicates that a stophas been made by the back gauge and paper pile for the cutting operationto take place for trim-out of the unprinted'strip of paper. f f Thepresent invention is particularly directed to the incorporation of anovel and effective electric motor driven mechanism for the back gaugeoperable in conjunction with the aforesaid photo-electric cell controlsystem to accomplish all of the aforesaid functions for the back gauge,to accomplish a predetermined and programmed rational relationship ofthe lback gauge, the stack of sheets on the work table, and its cuttingby the reciprocable knife. As will now be understood, precisepositioning of the back gauge is requisite under the control ofprecisely set stop units coactable with a light beam and photo-electriccells, and a control carriage movable in synchronism with the backgauge.

In accordance with the invention herein, a novel arrangement is providedincluding two motors both coupled to the driving member or lead screw ofthe back gauge; one is a high speed motor; the other a low speed motor;both preferably electric but may be hydraulic or other types. The shaftsof these two motors are coupled to the work table drive member throughindividual electro-magnetic clutches. A system of electrical control isprovided to actuate the high speed motor into forward or reverserotation as required in the cycling. The high speed motor when engagedmoves the back gauge forward or backwards at its rapid speed. Whenproperly `actuated by the control system, the low speed motor takes overto move'the back gauge towards an accurate position for cutting at itsslow speed, all as determined by a photo-electric control system andpreset stop program. The present invention is an improvement of themechanism and systems set forth in the aforesaid applications, affordingdirect positive actuation of the hack gauge in a foolproof andrelatively inexpensive and trouble-free system.

It is accordingly an object of the present invention to provide a novelsystem for operating the back gauge of a paper cutter either manually orautomatically through a novel arrangement of electro-mechanicalmechanisms.

A further object of the present invention is to provide an automaticback gauge spacing system incorporating a plurality of electric orhydraulic motors, electro-magnetic clutches, and photo-electric cellcontrols therefor actuated by a stop unit program.

A further object of the present invention is to provide an automaticand/or manual control system for back gauge operation of a paper cutter,providing all the requisite functions and operations of the back gaugethat a modern paper cutter requires, and affording a simple, direct andpositive drive action on the back gauge, either for fast forward orreverse, or slow and accurate stop positioning, all as programmedadvance.

Still another object of the present invention is to provide a novel,automatic back .gauge mechanism incorporating electric motor drives andelectro-magnetic clutches for directly operating the back gauge inresponse to predetermined stops programmed by the operator forsuccessive cutting positioning and/or trim-outs.

The foregoing and other objects of the invention will become moreapparent in the following description in conjunction with the drawingsin which:

Figure l is a side view of a reciprocable knife paper cutter machineembodying a preferred form of the present invention.

Figure 2 is a plan View of the paper cutter machine shown in Figure l. y

Figure 3 is an end view of the motor drive mechanism for the back gaugecorresponding to Figures 1 and 2, enlarged to show details thereof,beingthe viewtaken along the line 3-3 of Figure l in the direction ofthe arrows.

Figure 4 is a plan view of the motor drive mechanism shown in Figure 3,with the work table thereof partially broken away. Y

Figure 5 is a ydiagrammatic representationof the back gauge controlsystem and the motor drive mechanism schematically showing some of thecircuit elements thereof.

Figure 6 is a schematic electrical diagram of a preferred control systemthat is responsive automatically to photo-electric cells and/ or tomanual control, for operating the back gauge in a predetermined manner.

Figures l and 2 show a paper cutting machine comprising structuralarrangements similar to that shown in the aforesaid applications SerialNos. 200,013 and 391- 217. The paper cutting machine comprises a worktable carried between upright side frame casings 101, 101. Side framecasings 101, 101 are cross-braced by crossmember 102. The rear end(left) of work table 100 is supported by a bracket (not shown) whichalso may serve as a partial support for the back gauge operatingmechanism 125 to be described. Work table 100 and side frame members101, 101 extend from and are basically secured to housing 103 which alsocomprises the base for the cutter machine. The paper cutting mechanismcomprises a reciprocable knife blade arranged between side frame casings101, 101 and cross-bracing member 102 and not seen in the drawings. Asuitable clamping arrangement is generally provided with the cuttingknife mechanism. The mechanism for operating the reciprocable cuttingblade and clamp is generally contained underneath the work table 100 andwithin the housing 103. The cutting blade assembly and its operatingmechanism are shown in the drawings for clarity purposes as they form noparticular feature of novelty in the present invention, it beingunderstood that suitable kmeans well known in the art is utilizedtherefor.

Back gauge 105 comprises a metal casting 106 which extends acrosscutting tabel 100. Back `gauge 105 has a plurality of forward extensions107 seen in Figure 2. T-he aligned front edges of forward extensions 107form the back gauge surface which -coacts with the pile of 'sheets to becut by the machine. Work table 100 is provided with a centrallongitudinal slot 108 through which a depending bracket -110 of backgauge 105 extends downwardly. The slot 10S forms a vtrack for the backgauge bracket 110 and for the back gauge in its longitudinal traversealong work table 100. A nut 111 is formed in an extension of the backgauge bracket 110 which is in threaded engagement with the back gaugefeed screw 112.

L It is understood that rotation of feed screw 112 causes back gauge 105to longitudinally traverse work table 100 in a forwardly or rearwardlydirection depending on the sense of rotation of the yfeed screw; andthat the speed of traverse of back gauge 105 is proportional to ltherate of rotation of -the feed screw. Furthermore, in view of thepositive engagement between feed screw 112 and nut 111 of the backgauge, accurate positioning of the back gauge is feasible, as will beset forth hereinafter. v

Feed screw k112 is rotatably carried beneath slot 108 0f Work table 100-in front bearing 113 mounted under the forward extension 100e of table100 and the rear bearing at 114- under table 100. The front endy(right). of feed, screw 112 is provided with a hand wheel 115 for manualoperation of the -back gauge 105 through the feed screw. The rear end(left) of back gauge lead screw 112 is provided with a double pulley120. Two drive. belts ,121, 122 coact with pulley 120. through the motordrive mechanism 125 under the control of automatic and/or manual means,all to be described in detail hereinafter, and forming an essentialbasis of the present invention. Lead screw 112. is mounted so that whileit may rotate freely, -it has no longitudinal movement. Accordingly,rotation of screw 112 by either operating mechanism 125` through pulley120 or manually through hand wheel 115 results in a correspondinglongitudinal movement of the back gauge 105 across work tablev 100 at aspeed and direction in accordance with the rotation of lead screw 1'12.

The automatic operation of back gauge 105 through motor drive `system1251's under the control of a series of stop units preset along aprogram bar 126 and coactable with photofelectric cells contained inmovable carriage 127. The carriage 127 @averses across the front of themachine in synchronism with the longitudinal position of back gauge 105.Such inter-related motion is performed in a precise mannerV in orderthat the triggering of thephoto-electric cell and, in turn,` activationof motor control system 125,V will correspond directly to the intendedprogrammed action for the positionsv of back gauge 105. The positioningof carriage 127 along the front of the cutting machine is accomplishedas follows: Back gauge 105 is provided withl two depending lugs y132,8,129. A cable 130 terminates in the lugs 128 and 129 separately. Backgauge 105 is rmly coupled to carriage 127 by cable 1,30 being disposedacross the cutting machine in a series of sheaves 131 as detailed in thesaid `co-pending applications Serial Nos. 200,013 and 391,217. CableY130 is secured to carriage 127 at extending lugs 132, 132 thereof.

The overall extent of movement of carriage 127 across the front of theVmachine is equal to the full operating traverse of back gauge 105 onwork table 100. Figure 5 diagrammatically represents the relationship ofcarriage 127 and back gauge 105. A scale 133 is positioned neara readingopening -134 of carriage 127 and across the path of carriage 127 infront of the cutting machine. Scale 133 is graduated in inches orcentimeters as desired andn indicates the exact posit-ion of back lgauge105 through indicator 134. Since there is a one to` one relationship inthe movements thereof, the movement of carriage 127 exactly duplicatesthe movement of back gauge 105. Also, the exact location of back gauge105, or rather the exact distance of its operating front face 107 fromthe cutting knife, is thus directly known at all times by the operator.

Electric motor drive system The electric drive system 125 operates ontherear end of back gauge lead screw 112 through double grooved pulley120 secured to the lead screw. Figures 3 and 4 illustrate a particularembodiment for the motor drive 125 supported beneath the rear end (left)of the work table 100. Work table 100 is shown in dotted lines in thesetwo gures; and in the plan view Figure 4 is partially broken away toshow the supporting frame 135 for the drive assembly 125. The assemblyfor the drive mechanism 125 comprises two further frames namely bottom`frame 136 and vertical frame 137 secured between frames 135, 136.Electric drive motor 140 is secured to vertical frame member 137 by aseries of bolts 141 through mounting holes in its base 142. Electricdrive motor 145 is secured to bottom frame member 136 through suitablebolts 146. The cantilevered (right) side of frame member 136 issupported by stay bolts 147, 147 extending through and secured with topframe member 135. -Suitable struts and supporting members are utilizedY6 among the three frame members 135, 136, 137 to secure the motor drivestructure 125 rigidly as a sub-assembly.

Top frame member 135 is `secured to work table 100 by bolts 148extending through slots in frame member 135 to posts 150 extending fromthe lbottom of Work table 100. The motor drive assembly 125 isaccordingly adjustable in a direction transverse of work table for thepurpose of adjusting to a proper tension in the drive belt 121connecting pulley 120 with drive pulley 151. Drive pulley 151 is drivenby motor 145 in a manner to be described. Similarly, belt 122 connectsthe pulley 12.0 to the drive p-ulley 153 operated by electric motor 140in a manner to be set forth.

A set screw 153 is shown in Figure 3 for adjusting the said transverseposition of the motor assembly with respect to the fixedl position oflead screw 112. Set screw 153 is rotatably mounted in a threaded post154 extending from frame and is arranged to abut a post `150 in bed 100.Suitable rotation of set screw 153 creates a desired tension in belt 121between pulleys 120 and 151. Similarly, motor is slideably mountable onvertical` frame member 137, and a set screw 155, mounted in threadedpost 156 secured to frame 137, adjusts the position lof motor 140 onframe member 137 in a vertical direction. -In 4this manner, the tensionin belt 122 between pulleys 120 and 152 is suitably adjusted. Itis to beunderstood that the nuts on the respective bolts 141 and 148 aretightened when the proper tension in belts 121 and 122 are derived; andtha-t the bolts 157, 158 acting on set screws 153, in their respectiveposts 154, 156 also secure the set screws after the said adjustment.

Electro-magnetic clutches 160 and 161 are incorporated in the electricdrive system 125. Electro-magnetic clutch 160. is. arranged between theoutput shaft 162 of motor 145 and drive pulley 151; electro-magneticclutch 161 -between output shaft 163 of motor 140 and drive pulley 152.Electro-magnetic clutches 160, 161 may be of any suitable type andconstruction, a preferred embodiment employing the well-known Warnerclutches. Clutch 160 is connected to the electrical control systemthrough its coil leads 164 extending from electrical connection block165 of clutch 160. Block 165 is suitably mounted on bracket 166 fastenedto extension support 167, in turn secured to frame 137. Similarly,clutch 161 is connected to the control circuit through its coil leads168, extending from connection block 169 of clutch 161. Block 169 ismounted on bracket 170 suitably secured to extension bracket 167.

Figure 5 diagrammatcally illustrates the electric motive system 125 andits drive relationship with back gauge,

105 through lead screw 112. Electric motor 145 drives lead screw 112when its associated electric clutch 160 is engaged. Engagement ofelectric clutch 160 is accomplished when its clutch coil 171 is suitablyenergized by the control circuit through its leads 1764 in a manner tobe set forth hereinafter. Likewise, motor 140 -operates lead screw 112through belt 122 when its associated electromagnetic clut-ch 161 isactuated. Actuation of clutch 161 occurs when its clutch coil 172 issuitably energized yby the control circuits to be described, through itsleads 168.

In the illustrated embodiment, motor 140 is a reversible three-phasealternating current induction electric motor operating off a commercial60 cycle line. Motor 140 is herein the high speed motor termed H. S. M.In a suitable embodiment of system 125, the H. S. M. motor 140 operatedat 900, R. P. M. and had an output rating of 0.75 horsepower. Theelectric motor 145is also a three-phase 60 cycle induction motor, hereinthe low speed motor and termed L. S. M. Motor 145 is preferably lanindustrial gear motor shown in Figure 5 :as having step-down helicalgearing 173, 174. In the described embodiment, with output shaft 163 ofH. S. M. 140 operated at 900 R. P. M., the output shaft 162 of L. S. M.145 operates at the slow speed of 25 R. P. M.; and its output ratingbeing one-third horsepower.

Selective energization of clutch coils 171 and 172 cor` respondinglyfirmly connects pulleys 151 and 152 to the respective motors 145, 140through magnetic clutches 160, 161. L. S. M. 145 is operatedcontinuously in one direction when power line switch 179 is closed.Motor 145 is connected directly to line 177 extending from switch 179through leads 175. When clutch 160 of L. S. M. 145 is energized tooperate pulley 151, it is motivated in a predetermined direction at alow speed vof rotation, as is lead screw pulley 120. However, H. S. M.140 is connected to main line 177 through a motor starter unit 180 in amanner to be more fully described in connection with Figure 6 throughthree-phase leads 175 and 176. The motors are connectible normally forforward drive, 'and motor 140 by 'control -into reverse, as will bedescribed. Accordingly, the high speed drive pulley 152 is arranged toturn lead screw 112 in either direction and at the fast speed, inaccordance with the actuation through motor starter 180 and clutch 161.

Motor starter unit 180 comprises two solenoids: solenoid 181 for forwardor forward start, and solenoid 182 for reverse or Rev. Start, asindicated in Figures and 6. When Forward (Fd) Start solenoid 181 isenergized, normally open starter contacts 183 of motor starter 180 areclosed and directly connect leads 176 of motor 140 to the mainthree-phase line 177 through leads 178. The main power line 177 isconnected to the three-phase 60 cycle A. C. source through electricalswitch 179. When the Reverse (Rev.) Start solenoid 182 is insteadenergized, the three normally open contacts 184 of motor starter 180 areclosed thereby and in turn `also directly connect the motor leads 176 tomain line 177, except that two of these leads are reversed in theirthree-phase relationship as compared to the connections through contacts183. This causes lead reversal motor 140 to operate in the reversedirection, as will be further detailed.

Upon energization of Rev. solenoid 182 for reverse operation of motor140, the normally closed contact 185 rin the gang of contactors 184isopened to in turn break a possible circuit connection to the Forward(Fld) Start solenoid 181 in series connection. Thus, when reverse (Rev.)solenoid 182 is energized, the forward (Fd) Start solenoid 181 isdefinitely de-energized and the motor control unit 180 operates motor140 in only one direction, and at full speed in either direction.Solenoid 181 is connected to the control circuit, as shown in Figure 6,through the leads 186, 187 which carry solenoid 181 and contacts 185 inseries. The Rev. Start solenoid 182 is connected to the control circuitthrough leads 188, 189.

Back gauge control system The operation of back gauge 105 ispre-arranged by a programming procedure diagrammatically shown in Figure5. As hereinabove described, carriage 127 duplicates the movement of-back gauge 105. l/Vhen the back gauge 105 is all the way back, thecarriage 127 will be over to the right-hand side. As back gauge 105moves forward toward the cutting blade, the carriage 127 will move tothe left as viewed in Figure 5. Supported in carriage 127 arephoto-tubes 190 and 191 and a light source 192. A condenser lensarrangement 193 is mounted in carriage 127 between light source 192 andphoto-tubes 190, 191.

The photo-electric cells 190, 191 automatically operate the controlsystem to be detailed in connection with the description of Figure 6, bya change offillurnination, either from dark `to light or vice versa. Itis preferred that the photo-electric cells be illuminated from lightsource 192 while the back gauge 105 is travelling at its high speedcondition. sary for practical reasons to move the back gauge rapidlybetween cuts but to slow down the movement of the back gauge as the endof its movement before a cutting position approaches to prevent itscoasting and, therefore,that of the pile of paper beyond the cuttingpoint, when the back gauge is stopped. The control elements through Inthe operation of back gauge 105, it is neces-Y photo-electric cells 190,191 and the circuit operation on motor drive system accomplish thisrequisite function as will be hereinafter described.

The simplified control system and motor drive herein provides operationthat affords fast forward movement of the back gauge and then a slowforward movement thereof, as Well as an accurate stoppage thereof; andat the proper control actuation, fast reverse of the back gauge 105. Aseries of stop units 195 is disposed along a slotted hexagonal programbar 126 to define the operation of the motor drive 125 upon back gauge105. Stop units 195 comprise opaque shadow producing elements 196, 197,198 that intercept the light beam between source 192 and photo-cells190, 191 as carriage 127 moves with respect to the lstationary stops195.. When a right edge 197 'ofi'a stop-unit 195 interceptsv light tophoto-cell 191, the associated photo-relayPR-Z connected therewithisde-energized and arranged to slow down the fast forward drive of backgauge 105 through motor 140.

Further, lwhen projecting element 197 intercepts light to photo-cell190, photo-relay PR-l is de-energized and arranged to bring the slowmoving back gauge 105 to an abrupt stop. The operator thereupon actuatesthe cutting knife which, after abutting, recycles the automatic controlsystem to move backgauge 105 fast forward to- Wards the next cuttingposition, as will be set forth.

The exposed spaces 199 between depending opaque portions 197, 198 ofstop units 195 permit the slow speed operation of back gauge 105 untilthe back gauge is stopped again by depending elements 198. Thisarrangement corresponds to a trim-out cutting position. Where notrim-out is required, the sections 198 are removed from the stop units195 so that no spaces 199 exist at those sections of the program. Insuch case, only a single projecting unit corresponding to 195a remains.Such stop units 195a are used where no trim-outs are needed. f

Automatic electric control system Referring now to Figure 6, an overallschematic electrical representation is shown of the automatic electricalcontrol system, its circuits and the motor drive and clutch connectionstherewith. The system is arranged with the low speed motor (L. S. M.)running continuously, being directly energized from three-phase powerlines 177 through its leads 175. The back gauge 105 is moved forward bymotor 145 at a low speed when the low speed clutch (L. S. Cl.) isenergized by associated circuitry. Promptly upon the energization of L.S. clutch coil 171, the low speed clutch 160 engages the drive pulley151 to the back gauge pulley 12u with the output shaft 162 to the lowspeed motor 145.

The high speed motor (H. S. M.) 140 is connected to run continuouslyforward, i. e. in the direction of rotation that would carry back gauge105 in the forward direction at fast speed (when its associated clutch161 is engaged through energization of H S. Cl. coil 172). In otherwords, the forward (F'd) VStart solenoid 181 is normally engaged in theposition for the automatic operation to be described. However, wheninstead the Rev. Start solenoid 182 is energized, H. S. M. 140 operatesin the reverse direction. The back gauge 105 is moved in reverse at thefast speed (when the motor 140 clutch 161 is engaged throughenergization of H. S. Cl. coil 172).

Relay PR-l is a photo-electric relay. When light strikes light sensitivephoto-tube connected to this relay, the normally open contacts PR-1 areclosed. When the light beam is shaded by a stop unit 195, relay PR-1 isde-energized, and contacts PR-1 are opened.

Relay PR-2 is a photo-electric relay coacting with a different part ofstop units 195. This relay PR-2 likel wise is energized when the lightstrikes itsassociated light PR-Z to close. When the light is shaded bystop unit 195, contact PR-Z opens.

Relay CR-3 is an electrically operated but mechanically held relay. Whenits coil "a is energized, it operates to close a normally lopen contactCR-3 and to open -a normally closed contact CR-S. As soon as thiscondition is reached, a switch (not shown) which is connected to thesolenoid a opens the circuit through the solenoid, but the contacts CR-3remain latched in their position after a is de-energized. To reverse themovement of these contacts, coil "b must be energized, and that tripsthese contacts to their normal unenergized position. The current throughcoil b is likewise interrupted by a switch (not shown) connected to it.in this relay, CR-3, therefore, the coils are energized during theclosing and nonlatching `operations only and remain de-energized therest of the time.

Relay CR-4 contains contacts CR-4 for selectively controlling theenergization of the direct current clutch coils 171, 172 in combinationwith relay CR-Z, as will be described.

A. rectier unit 200 is provided within the control circuit, the output7'1, 72 of which is 90 volts direct current, in turn connected to theelectromagnetic clutch coil circuit terminal 71, 72.

The electrical control system is connected between power lines L1 andL2, providing ll() volts alternating current thereto.

Relay MR-201 is a motor actuated relay. Contacts 202 of relay M12-201are connected in line L2. When the motor lines 177 are energized,solenoid 203 of motor relay MR-202 is, in turn, energized to close itscontacts 202 and' provide the full control voltage to terminals 12 ofthe circuit. Thus, the control system is inoperative unless. motor relayMR-201 is energized by the motor line operation.

A step-down transformer 205 is connected between terminals 12, 29 and 3through control resistor 206 to provide 6 volts A. C. to pilot lights207' (1) and 208 (P). A fuse 209 is connected between points 1 and 3 ofthe control circuit.

The Forward Start (Fd) control solenoid 181 of starter 180 is connectedto terminal 12 and line L2 by its contact 186; and, as described, inseries with normally closed reverse start contact 185, through terminals91, 92, and in turn, through connection 187 through the contacts ofnormally closed Rev. (reverse) button 210 to the opposite potential 3and line L1. Thus, unless the manual reverse starter buttonA Rev. 210 isactuated, the forward (Fd) Start solenoid 181 is in normal circuitenergization and the motor starter contacts 183 closed to directlyconnect high speed motor H. S. M. 140 to the power lines 177. It is tobe understood that although the motor 140 is continuously rotatingcorresponding to a forward direction of back gauge 105, the back gaugelead screw 112 is not actuated by the motor 140 unless the associatedmotor clutch 161 is energized through its H. S. coil 172, as will bemore evident hereinafter. Clutch coil 1.72 is not energized unless therelay CR-4 is energized.

The high speed motor 140 is made to rotate in its reverse direction whenthe Rev. (reverse) push button 210 is pressed down manually. With Rev.button 210' of Figure 6 moved downwardly, the circuit between points 3and 187 is open, and energization to the Fd Start motor coil 1&1 isinterrupted. At the same time, the portion of Rev. switch 210 acrosspoints 6-10 of the circuit is bridged to energizeirelay CR-1 acrossreverse limit switch R. L. S. from terminal 5, and through to 12 acrossmanual Stop switch 211, the function of which is to be detailed.Energization of relay CR-l causes the reverse (Rev.) Start solenoid 182of starter 180 to be in circuit: across 189;-188-9, across limit switchSGLS67, across contacts CR-1 at 7-8 and through the normally closed con-10 tacts 8--189 of Fd switch 2.15, to terminal 12, across Stop switch211v Thus, the manual Reverse Rev. switch 210, when pressed in, opensthe Fd Start solenoid 181 circuit and engages into energization the Rev.Start solenoidy 132. The motor starter 180 thereupon connects motor 140in reversed direction of rotation and at full speed. When the H. S.clutch coil 172 is energized (with the energization of relay CR-4) thelead screw 112 is rotated in the direction to move the back gaugerearwardly and at high speed. The rearward movement of back gauge 105continues until either the operator presses the Stop switclr 211 to openthe solenoid 182 circuit or when the reverse limit switches RLS or SGLSare tripped or when the overriding Fd switch 215 is pressed (8--189lOther limit switches are incorporated in the control circuit: H. W. L.S. 3--27; Hex. B. L. S. 27-5, and F. L. S. 5-20. These limit switchestogether with RLS and SGLS, as described in the aforesaid applications,not only limit the rearward motion ofthe back gauge but also limit theforward motion and intermediate positions on its backward travel, asdesired. This prevents the back gauge 105 jamming into the front or rearof the cutting machine and to ensure its stopping at an intermediateposition when desired.

Automatic back gauge spacer operation The selector switch 212 is movedto its automatic position (A) whereby its contacts are as shown inFigure 6: bridging points 20 and 21 in the circuit; and contacts 20-17remain open. When selector switch 212 is moved to the central or (O)position, the control circuit is off; when thrown to H position, it isin the manual position of operation.

Automatic operation is provided by the signals from the photo-electriccells 190 and 191 coacting with the program of stops 195 as heretoforeset forth. The automatic operation is started by pressing the forward Fdpush button 215. This causes contacts 21 and 24 to be bridged toenergize coil a of relay CR-3 across potential terminals 21--12. Asdescribed above, the normally open contact of CR-3 (19-14) remainsmechanically closed until coil b of the relay is energized subsequently.When the forward (Fd) push button 215 is released (up), the contacts14-16 are bridged, to energized the relay CR-Z at 16--9 as CR-3 contacts19-14 are closed; and thus relay CR-Z is across the full voltage 21-12.

Energization of relay CR-Z closes contacts CR-Z across terminal 72-73 ofthe clutch coil circuit. This in turn engages the L. S. clutch coil 171through the normally closed contact CR-4 at 73-74 to potential 71. Thus,the pressing of Fd button 215 and its subsequent release resuits in theenergization of the L. S. clutch coil 171 and in turn engages itsassociated clutch to directly connect the output of low speed shaft 162from continuously rotating L. S. motor 14S. The back gauge 105accordingly moves forward at the slow speed. Movement of the back gauge105 slowly forward also results in a corresponding motion of thecarriage 127 to the left' until a portion of the stop signal 195 inposition when the Fd button was pressed uncovers an aperture tophoto-electric cell 190. The beam of light accordingly impinges onphoto-electric cell and causes its associated relay l'R-l to beenergized.

This actuation transfers the control system to the automatic controlthrough the photo-cells. The two normally open contacts PR-1 are closedas soon as relay PR-l is energized through photo-cell 190, the terminals18-16 keeping relay CR-Z energized across terminals 21-12 and 13--9-21The PR1 contacts 19-22 thereupon energize coil b of relay CR-Sv whichopens up the contacts CR-3 at 19-14. Thus, when light impinges onphotoelectric cell 190, the starting relay CR-3 is thrown out of thecircuit, and photo-electric cell operation of the 11 automatic system isinstituted. During this state of energization of relay PR-l (with relayPR-Z unenergized), the relay CR-Z remains energized, and the low speedclutch 169 is engaged, moving the back gauge forward continuously at theslow speed.

Nhen the stationary stop 195 causes the aperture to the otherphoto-electric cell 191 to be uncovered and have light impinge upon it,its associated relay PR-Z becomes energized. Energization ofphoto-electric cell 191 sirnultaneously with energization ofphoto-electric cell 190 results in the fast forward operation of theback gauge 105 for the reasons now to be described.

Relay CRM@ is incorporated in the control circuit with its contactsarranged in the electro-magnetic clutch system. Energization of therelay CR-4' results in its contacts at 72-72 to close; its normallyclosed contacts (1R-4 at 73-74 to open; and its normally-closed contactsat 73--75 to close. The H. S. Cl., high speed clutch coil 172, becomesenergized across the full 90 volts direct current line 72-71. With relayCR-4 (1S-9) energized, the clutch coil 172 thereupon becomes directlyenergized, and the low speed clutch coil 171 is disconnected from the D.C. circuit. The high speed clutch 161 is then directly engaged, causingthe high speed motor 140 to move the back gauge .105 forward at a fastspeed (since the forward start solenoid 181 is normally in circuit).

Relay Cil-4 is energized by the closure of contacts PR-Z (when relayPR-2 is energized) at 21-21c1 but only when the corresponding contactsClit-2 in series therewith at 21a- 15 are closed. In other words, thehigh speed clutch operating relay CR-l cannot be energized by the PR2contacts (Z1-21a) alone, unless the relay CR-2 (1o-9) is also inenergization to close contacts 21a-15. During automatic photo-electriccell operation, relay CR-2 can only remain energized by the bridging ofcontacts 19-18 when photo-cell 190 is lighted to energize photo-relayPR-1. This is also a safety feature as will be later explained.

Thus, when the light beam impinges on photo-cell 191, as well as uponphoto-cell 190, the high speed clutch relay C11-4 is energized acrossthe contacts 21-Z1a and 21a- 15. This action engages the high speedclutch coil 171 while also causing the disengagement of low speed clutchcoil 171 across i3-74. The motor 140 thereupon moves the back gauge 105forward at the fast speed during the simultaneous impingernent of thelight beam on cells 190 and 191 in accordance with the arrangement bystop signals 195.

Automatic stopping of the back gauge to accurate predetermined positionsis accomplished in two steps: The rst step is to provide a signal thatresults in the back gauge being moved into the slow speed from a fastforward speed operation; and then, at the proper time, de-energize theslow speed forward position when the back gauge will directly stop. Thisis accomplished by arranging the stop signal 195, which at this pointhas the light beam impinged upon both cells 190, 191, to tirstde-energize the photorelay Pil-2 by causing the light beam to be stoppedor opaqued in its passage to photo-cell 191. De-energization of relayPil-2 causes the contacts 21-21fz to open, to in turn de-energize relayCR-4. Release of relay CR- opens contacts 72-73-75 at the H. S. clutchcoil 172 disengaging the high speed motor 140 from its driving of backgauge S. Simultaneously, the relay PR-1 remains energized, since lightis still arranged to be impinging ou its photo-cell 190. This means thatthe relay CR-Z still remains energized and, therefore, its contacts72-73 are closed while the de-energization of relay l-treturns thenormally closed contacts thereof (731-76) into engagement to completethe circuit through the low speed clutch coil 171.

When it is thereupon desired to stop the back gauge 105, the stopsignals' 195 are arranged to intercept the light beam to cell 190 (aswell as tocell 191 already opaqued). This action deenergizes theassociated relay 12 PR-l and opens the PR-l contact at 19-18. Relay CR-Zis thereupon deenergzed to open its contact 72-73 at the clutch circuitand deenergize the low speed magnetic clutch coil 171. With both clutchcoils thus deenergized, the slow moving back gauge is stopped withoutovershoot and in an accurate predetermined position.

summarizing the automatic action, the starting (forward) button Fd 215is pressed, starting the back gauge moving forward slowly, until onephotoelectric relay aperture (to cell 190) is uncovered. The light beamcontrol and the next stop unit takes over automatic operation `of theback gauge until the next cutting position. With light arranged by stop195 for impingement on both photocells 190 and 191, the high speedclutch coil 172 is engaged and the back gauge moves forward at the fastspeed. When the stop unit 195 is arranged for the light to photo-cell191 to be covered up, the high speed clutch coil 172 becomes disengagedand the low speed clutch coil 171 engaged to move the back gauge forwardslowly. With the stop unit 195 arranged to Shield the light tophoto-cell 190 (as well to cell 191) energization of the low speedclutch 160 ceases, and the low speed moving back gauge 105 stopsabruptly at the predetermined position.

A green signal light G is energized and lights up indicating that acutting operation on the pile of sheets may be made when a preset newposition of the back gauge is thus reached. After the cutting operationon the paper sheets is completed and the knife and clamp are on theirway up to their rest `or nesting position, a knife switch KN 21-28 isclosed to start the automatic cycle all over again (in a manner similarto the recycling by pressing of Fd button 215 across 21-24). It is to beunderstood that the knife switch KN (2l-28) is closed only while theknife is moving upwardly and is opened again to the indicated positionin Figure 6 when the knife is nested.

Three normally closed switch contacts are in series with green light Galong 19-12, 13R-1, CR-l and CR-3 as described in the co-pendingapplication Serial No. 391,217. During any motion of the back gauge 105,whether forward or reverse, or fast or slow, `one of these normallyclosed switches along the circuit 19-12 including lamp G is open, andthe lamp does not indicate. However, as soon as motion of the back gaugestops, the three switches are again all normally closed, and the bulb Glighted up, indicating that a cutting operation may be made. Suchoperation of the cutting indicator lamp G occurs during Veither manualor automatic operation of the system.

When the selector switch 212 is in the automatic position A, pushing ofthe reverse butt-on Rev. 210 at any time in its cycle will cause theback gauge 105 to move in the reverse direction and at fast speed. Ifthe Fd button 215 happens to be pressed down at the same time that thereverse button 210 is down, its normally closed contacts 8-189 will keepthe Rev. Start solenoid 182 cle-energized and slow forward motion of thebackgauge 105 will result. Thus, Fd button 215 at slow forward overridesthe Rev. button 210 for fast reverse. The Fd contacts across 18-16energize the slow speed clutch relay CR-Z.

As heretofore described, the photo-electric cell PR-l cannot energizerelay (DR-2 (16-9) unless the forward (Fd) push button 215 is presseddown temporarily or the knife switch 21-28 is engaged by the operator.The reason is that when relay CR-2 is rie-energized, its contact CR-Zacross 18-16 is open and PR-l cannot close the circuit to the relayC11-2. It is necessary for relay CR-Z to rst be energized by the othermethod, either through the Fd switch 215 or the KN switch. Then theVcontacts CR-Z at 13-16 are closed, and the photo-relay PR-l can takeover. This also provides a safety measure in case both apertures to thephotocell 190 and 191 are unshaded at the time the selector switch 212is thrown 13 into automatic (A); no motion of the back gauge 105 willoccur at all even though the light is shining both photo-cells 190, 191,until either the operator presses the Fd button or the KN contacts areclosed in the normal cycle of operation of the machine.

Thus, it is now apparent that the Fd button 215 overrides the action ofRev. button 210 if both are pressed together and that slow forward speedof back gauge 105 results with the pressing down of Fd button 215, Whilein automatic (A) selection. When Fd button 215 is released, theautomatic programmed forward motion of back gauge 105 takes place underthe co-action of stop units 195 and photo-electric cells 190, 195 -asdescribed. Pressingof Stop button 211 will further override the actionof both Rev. button 210 and Fd button 215 and also of the automaticcontrol by photo-cells 190, 191. When Stop button 211 is pressed, itopens the control circuit across 9-12, deactivating any possible actionon high speed clutch control relay CR-4; or on the low speed clutchcontrol relay CR-2, as well as on Rev. Start solenoid 182. Thus, backgauge 105 cannot be moved while the Stop button 211 is pressed down bythe operator.

Stop button 211 also, when pressed, closes across contacts 21-23 toenergize the Open coil b of relay CR-3`, which resets contacts CR-3 totheir normal position before energization of coil a. Thus, to enableautomatic control through photo-electric cells 190, 191, recycling isnecessary by either pressing and then releasing Fd button 215, or by KNknife switch action. A snap switch Y is provided' at 28-24 to preventautomatic action of the system by photo-cells 190, 191 at the will ofthe operator, by overriding the recycling action of knife blade switchKN at 21-28.

Manual operation of system To operate the back gauge 105 of the cuttingmachine by manual control, the selector switch 212 is moved to the Hposition. This shift of selector 212 opens the control line L1 circuitbelow terminal 20: to the relays PR-L PR-2, CR-Z and CR-S; and closesthe circuit across 20-17 that leads to relay CR-t across normal openedcontacts 17-15 of Fd button 215. Pressing of Fd button 215 manuallythereupon directly energizes relay CR-4 at 15-9. This causes contactsCR-4 across 72--73 and. 73-75 to energize H. S. clutch coil 172. Theback gauge 105 thereupon moves forward at fast speed since the H. S.motor 140 is in its normal forward speed operation by the normalengagement of Fd Start solenoid 181. When Fd button 215 is released,back gauge 105. stops, as clutch 161 is disengaged when its coil 172 isdeenergized.

Reverse motion is imparted to back gauge 105 by pressing the Rev. button210. Rev. Start solenoid 182 of motor starter 180 is thereuponenergized, since relay CR-l closes its contacts across 7 8'. Thenormally engaged Fd start solenoid 131 is disconnected across 3-187 toensure only the reverse operation of motor 104. An additional safetymeasure is the opening of normally closed contacts 185 in the reversecontacter gang operated by solenoid 182. Relay CR-1 also closes the;circuit across -15 to engage relay CR-dl at 15-9.

Thus, H. S. clutch coil 172 is energized to engage clutch 161'.` betweenS. motor 140: and they back gauge lead screw 112. Back gauge 105 isthereupon moved in reverse at the fast speedV until the reverse circuitis interrupted by either release of Rev. button 210; pressing of Stop.switch 211; or opening up of reverse limit switches R. L. S'. or S. G.L. S. at 5 6 or 6 7; Clutch` coil 172 becomes de-energized to disengageH. S. clutch 1161, whereuponl back gauge 105 stops. Motor 140 resumesits forward direction when the Fd Start solenoid 181. is re-energized'upon release of Rev. button 210.

In the foregoing the invention has been described in connection with apreferred embodiment for illustrative purposes. The electric motors and145 described may be replaced by suitably controlled hydraulic motors,or other mechanical equivalent drives. Variations will now becomeapparent to those skilled in the art, and it is not intended 'to belimited except as set forth in the following claims.

We claim:

1. Spacer mechanism for a machine. having a work table, a back gaugemovable linearly across the work table embodying a series of stopsignals for predetermining the positions of the back gauge comprising aseries of signal elements. arranged in succession in accordance withdesired work positions and speeds of movement of the back gauge; motormeans; driveable means connecting the back gauge with the output of saidmotor means including clutching means with rst' and second solenoids forcontrollably effecting movement of the back gauge by said motor means;and circuit means for controlling the movement of the back gauge inaccordance with said series of stop signals comprising first signalresponsive means arranged to engage the rst solenoid to drive the backgauge forward at slow speed in response to first arrangements of saidsignal elements, and second signal responsive means. arranged to engagethe second solenoid to drive the back gauge forward at fast speed inresponse to second arrangements of said signal elements, said first andsecond signal responsive means being mechanically coupled to move withthe back gauge, andy said. signal elements being stationary with respectto the Work table.

2. Spacer mechanism for a machine having a work table and a back gaugemovable linearly across the work table embodying a series of stopsignals for predeterminingl the positions of the back gauge comprising aseriesy of signal elements arranged in succession in accordance withdesired work positions and speeds of movement of the back gauge; a firstmotor having a relatively slow speed output shaft continuously rotatablein the forward direction, a second motor reversibly operable and havinga relatively fast speed output shaft; driveable means connecting theback gauge with the output shaft of each of said motors including a rstand second clutch, respectively, for selectively engaging said motoroutput shafts to correspondingly move the back gauge Valong the worktable; and circuit means for controlling the movement of the back gaugein accordance with said series of stop signals comprising firstsignalresponsive. means arranged to engage said first clutch to drivethe back gauge forward at slow speed in response to first arrangementsof said signal elements, and second signal responsive means arranged toengage said second clutch to drive said back gauge forward at fast speedinV response to second arrangements of said signal elements, said rstand second signal responsive means being mechanically coupled with saidback gauge.

3. Spacer mechanism for a machine having a work table, a. back gaugemovable linearly across the work table embodying a series of stopsignals for predetermining the positions of the back gauge comprising aseriesof signal elements arranged in succession in accordance withdesired work positions and speeds of movement of the back gauge; a firstmotor having a relatively slow speed output shaft continuously rotatablein the forward direction, a second motor reversibly operable and havinga relatively fast speed output shaft; driveable means connecting theback gauge with the output shaft of each of said motors including afirst and second clutch, respectively, for selectively engaging saidmotor output shafts to correspondingly move the back gauge along thework table; circuit means for controlling the movement of the back gaugein accordance with said series of stop: signals comprising rst signalresponsive means arranged to engage said rst clutch to drive the backgauge forward at slow speed in response to first arrangements of saidsignal elements, and second signal responsive means arranged to engagesaid second clutch to drive said back gauge forward at fast speed inresponse to second arrangements of said signal elements, said first andsecond signal vresponsive means being mechanically coupled with saidback gauge with relay means in circuit with said lirst and second signalresponsive means for engaging only said second clutch when said signalresponsive means are simultaneously activated, whereby the back gauge ismoved fast forward upon activation of both said signal responsive means,slow forward upon activation of said first signal responsive meansalone, and is stopped when neither of said signal responsive means isactivated oy the said signals.

4. Spacer mechanism for a machine having a work table, a hackl gaugemovable linearly across the work table embodying a 'series of stopsignals for predetermining the positions of the back gauge comprising aseries of signal elements arranged in successiorin accordance withdesired work positions and speeds of movement of the back gauge; a firstmotor having a relatively slow speed output shaft continuously rotatablein the forward direction, a second motor reversibly operable and havinga relatively fast speed output shaft; driveable means connecting theback gauge with the output shaft of each of said motors including afirst and second clutch, respectively, for selectively engaging saidmotor output shafts to correspondingly move the back gauge along thework table; circuit means for controlling the movement of the back gaugein accordance with said series of stop signals comprising firstphoto-electric responsive means arranged to engage said first clutch todrive the back gauge forward at slow speed in response to firstarrangements of said signal elements, and second photo-electricresponsive means arranged to engage said second clutch to drive saidback gauge forward at fast speed in response to second arrangements ofsaid signal elements, said irst and second photo-electric responsivemeans being mechanically coupled with said back gauge with relay meanspermitting the engagement only of said second clutch, whereby the backgauge is moved fast forward upon activation of both said first andsecond photo-electric responsive means, slow forward upon activation ofsaid first photo-electric responsive means alone, said signal elementsbeing arranged to lower the speed of the back gauge before its stoppingby activating the first photoelectric responsive means alone to move theback gauge into slow speed before deactivating both photo-electricresponsive means together, whereupon the back gauge is accuratelystopped at the predetermined position.

5. Spacer mechanism for a machine having a work table, a back gaugemovable linearly across the work table embodying a series of stopsignals for predetermining the positions of the back gauge comprising aseries of signal elements arranged in succession in accordance withdesired work positions and speeds of movement of the back gauge; a firstmotor having a relatively slow speed output shaft continuously rotatablein the forward direction, a second motor reversibly operable and havingVa relatively fast speed output shaft; driveable means connecting theback gauge with the output shaft of each of said motors including aiirst and second clutch, respectively, for selectively engaging saidmotor output shafts to correspondingly move the back gauge along thework table; circuit means for controlling the movement of the back gaugein accordance with said series of stop signals comprising first signalresponsive means arranged to engage said first clutch to drive the backgauge forward at slow speed in response to first arrangements of saidsignal elements, and second signal responsive means arranged to engagesaid second clutch to drive said back gauge forward at fast speed inresponse to second arrangements of said signal elements, said first andsecond signal responsive means being mechanically coupled with said backgauge; and manually operable reversing means for motivating said secondmotor and correspondingly the back gauge in fast speed reverse movement,overriding any 16' engagement by the signal responsive means to drivethe back gauge;

6. Spacer mechanism for a machine having a work table and a back gaugemovable linearly across the work table embodying a series of stopsignals for predetermining the positions of the back gauge comprising aseries of signal elements arranged in succession in accordance withdesired work positions and speeds of movement of the back gauge; a firstmotor having a relatively slow speed output shaft continuously rotatablein the forward direction, a second motor reversibly operable `and havinga relatively fast speed output shaft; driveable means connecting thebackgauge with the output shaft of each of said motors including a firstand second clutch, respectively, for selectively engaging said motoroutput shafts to correspondingly move the back gauge along the worktable; circuit means for controlling the movement of the back gauge inaccordance with said series of stop signals comprising firstphoto-electric responsive means arranged to engage said first clutch todrive the back gauge forward at slow speed in response to firstarrangements of said signal elements, and second photo-electricresponsive means arranged to engage said second clutch to drive saidback gauge forward at fast speed in response to second arrangements ofsaid signal elements, said first and second photo-electric responsivemeans being mechanically coupled with said back gauge with relay meanspermitting the engagement only of said second clutch, whereby the backgauge is moved fast forward upon activation of both said first andsecond photo-electric responsive means, slow forward upon activation ofsaid rst photo-electric responsive means alone, said signal elementsbeing arranged to lower the speed of the back gauge before its stoppingby activating the first photoelectric responsive means alone to move theback gauge into slow speed before deactivating both photo-electricresponsive means together, circuit meansl arranged to stop the backgauge accurately at the predetermined positions when neither of saidphoto-electric responsive means is activated by said signal elements;and manually operable reversing means for motivating said second motorand correspondingly the back gauge in fast speed reverse movement,overriding any engagement by the photo-electric responsive means todrive the back gauge comprising a motor starter unit for the secondmotor having a forward and reverse solenoid, said forward solenoid beingnormally energized to keep said second motor` output in forwardoperation, a manual reverse control,` said reverse solenoid beingenergized upon activationof said manual reverse control to disconnectsaid forward solenoid and to engage the second motor output into fastreverse operation and disconnect said irst photo-electric responsivemeans from operating the first clutch.

7. Mechanism of the character described for a machine having a worktable and a back gauge movable linearly across the work tablecomprising: a first electric motor drive having a realtively slow speedoutput shaft continuously rotatable in the forward direction; a secondelectric motor drive reversibly operable and having a relatively fastspeed output shaft; driveable means connecting the back gauge with theoutput shaft of each of said electric motor drives including a first andsecond clutch for selectively engaging said rst and second electricmotor drives, respectively, to correspondingly move the back gauge alongthe work table; a series of stop signals for predetermining thepositions of the back gauge including a series of signal elementsarranged in succession in accordance with desired work positions andspeeds of movement of the back gauge and circuit means for controllingthe movement of the back gauge in accordance with said series of stopsignals comprising first photoelectric responsive means arranged toengage the first clutch to drive the back gauge forward at slow speed inresponse to first arrangements of said signal elements, and econdphoto-electric responsive means arranged to env17 gage the said secondclutch to drive the back gauge forward at fast speed in response tosecond arrangements of said signal elements, said first and secondphoto-electric responsive means being mechanically coupled to move withthe back gauge, and said signal elements being stationary with respectto the work table.

8. Mechanism of the character described for a machine having a worktable and a back gauge movable linearly across the work tablecomprising: a first electric motor drive having a relatively slow speedoutput shaft continuously rotatable in the forward direction; a secondelectric motor drive reversibly operable and having a relatively fastspeed output shaft; driveable means connecting the back gauge with theoutput shaft of each of said electric motor drives including a first andsecond clutch for selectively engaging said rst and second electricmotor drives, respectively, to correspondingly move the back gauge alongthe work table; a series of stop signals for predetermining thepositions of the back gauge including a series of signal elementsarranged in succession in accordance with desired work positions andspeeds of movement of the back gauge circuit means for controlling themovement of the back gauge in accordance with said series of stopsignals comprising rst photo-electric responsive means mechanicallycoupled with the back guage and arranged to engage the first clutch todrive the back gauge forward selectively at slow speed in response torst arrangements of said signal elements, second photoelectricresponsive means mechanically coupled with the back gauge and arrangedto engage the second clutch to drive said back gauge forward at fastspeed in response to second arrangements of said signal elements; andmeans permitting the engagement only of said second clutch when bothsaid photo-electric responsive means are simultaneously activated,whereby the back gauge is moved fast forward upon activation of bothsaid photo-electric responsive means, slow forward upon activation ofsaid rst photo-electric responsive means alone; and circuit elementsarranged to stop the back gauge when neither of said photo-electricresponsive means is activated by said signal elements.

9. Mechanism of the character described for a machine having a worktable and a back gauge movable linearly across the work tablecomprising: a first electric motor drive having a relatively slow speedoutput shaft continuously rotatable in the forward direction; a secondelectric motor drive reversibly operable and having a relatively fastspeed output shaft; driveable means connecting the back gauge with theoutput shaft of each of said electric motor drives including a first andsecond clutch for selectively engaging said first and second electricmotor drives, respectively, to correspondingly move the back gauge alongthe work table; a series of stop signals for predetermining thepositions of the back gauge including a series of signal elementsarranged in succession in accordance with desired work positions andspeeds of movement of the back gauge circuit means for controlling themovement of the back gauge in accordance with said series of stopsignals comprising first photo-electric responsive means mechanicallycoupled with the back gauge and arranged to engage the first clutch todrive the back v gauge forward selectively at slow speed in response tofirst arrangements of said signal elements, second photo-electricresponsive means mechanically coupled with the back gauge and arrangedto engage the second clutch to drive said back gauge forward at fastspeed in response to second arrangements of said signal elements; andrelay means in circuit with said first and second photo-electricresponsive means for engaging only said second clutch when both saidphoto-electric responsive means are simultaneously activated, wherebythe back gauge is moved fast forward upon activation of both saidphoto-electric responsive means, and slow forward upon activation ofsaid first photo-electric responsive means alone, said signal elementsbeing arranged to lower the speed of the 18 back gauge before itsstopping by activating said lirst photo-electric responsive means aloneto move the back gauge into slow speed before deactivating both saidphotoelectric responsive means together; and circuit elements arrangedto stop the back gauge accurately at the predetermined positions whenneither of said photo-electric responsive means is activated by saidsignal elements.

l0. Mechanism of the character described for a machine having a worktable and a back gauge movable linearly across the work tablecomprising: a first electric motor drive having a relatively slow speedoutput shaft continuously rotatable in the forward direction; a secondelectric motor drive reversibly operable and having a relatively fastspeed output shaft; driveable means connecting the back gauge with theoutput shaft of each ofy back'gauge in fast speed reverse movement,overriding any I engagement by said first clutch to drive the backgauge.

11. Mechanism of the character described for a machine having a worktable and a back gauge movable linearly across the work tablecomprising: a first electric motor drive having a relatively slow speedoutput shaft continuously rotatable in the forward direction; a secondelectric motor drive reversibly operable and having a relatively fastspeed output shaft; driveable means connecting the back gauge with theoutput shaft of each of said electric motor drives including a first andsecond clutch for selectively engaging said iirst and second electricmotor drives, respectively, to correspondingly move the back gauge alongthe work table; a series of stop signals for predetermining thepositions of the back gauge including a series of signal elementsarranged in succession in accordance with desired work positions andspeeds of movement of the back gauge circuit means for controlling themovement of the back gauge in accordance with said series of stopsignals comprising first photo-electric responsive means mechanicallycoupled with the back gauge and arranged to engage the first clutch todrive the back gauge forward selectively at slow speed in response toirst arrangements of said signal elements, second photoelectricresponsive means mechanically coupled with the back gauge and arrangedto engage the second clutch to drive said back gauge forward at fastspeed in response to second arrangements of said signal elements; andmanually operable reversing means for motivating said second motor andsecond clutch and correspondingly the back gauge in fast speed reversemovement, overriding any engagement by the first photo-electricresponsive means to drive the back gauge, comprising a forward and areverse solenoid, said forward solenoid being normally energized to keepsaid second electric motor drive in forward operation, a manual reversecontrol, said reverse solenoid being energized upon activation of saidmanual reverse control.

12. Mechanism of the character described for a machine having a worktable and a back gauge movable linearly across the work tablecomprising: a first electric motor drive having a relatively slow speedoutput shaft continuously rotatable in the forward direction; a secondelectric motor drive reversibly operable and having a relatively fastspeed output shaft; driveable means connecting the back gauge with theoutput shaft of each of said electric motor drives including a iirst andsecond clutch for selectively engaging said first and second electricmotor drives, respectively, to correspondingly move the back gauge alongthe work table; a series of stop signals for predetermining thepositions of the back gauge including a series of signal elementsarranged in succession first arrangements of said signal elements,second photoelectric lresponsive means mechanically coupled with theback gauge and arranged to engage the second clutch to v drive said backgauge forward at fast speed in'response to second arrangements of saidsignal elements; relay'meansr in circuit with said rst and secondVphoto-electric responsive means for engaging only'said second clutchwhen both'said photo-electric responsive means are simultaney ouslyactivated, whereby the back gauge is moved faste `15 sponsive means, andslow forward upon activation of said first photo-electric responsivemeans alone, said signal' elements being arranged to lower the speed ofthe back gauge before its stopping by activating said first photo-i v2,0into vslow speed before deactivating both said photo-elec@ tricresponsive means together; circuit elements'arranged I to stop the backgauge accurately at therpredetermined forwardupon activation of bothsaid photo-electric reelectric responsive means alone to move the back igauge positions when neither of said photo-electric responsive meansisactivated'b'y said signal elements; and manually operable reversingmeansifor motivatinglsaidy second motor andsecondrclutch andcorrespondingly the?ba'clcL'gau'ge'`V in Vfast speed reverse movement,overriding any er'igage-V ment by said first photoa'electric responsivemeans to drive* the back aguge, comprising a motor starter funit-forfthef second ,-motor'havingv a forward and 'a reverse solenoid, Ysaid foriv'vardsolenoid being normally energized to keep the secondelectric motor 'drive in forward operation-,V-a '1 manual lreversecontrol, said reverse 'sole'noid being ener'- rst clutch.

References Cited in thefile of this patent Y "UNITED STATES PATENTS

